Salt composition



Patented Dec. 29, 1953 SALT COMPGSITION Frank G. Miller, Denville, N. J., assignor, by mesne assignments, to Diamond Crystal Salt 00., St.

Clair, Mich., a corporation of Michigan No Drawing. Application July 28, 1950, Serial No. 176,517

Claims.

This invention relates to an improved salt composition, and more particularly to such a composition which is both free-flowing and noncaking when exposed to humid conditions for extended periods of time.

In humid weather salt absorbs moisture from the air with the result that it will not flow freely from salt shakers which creates a shaker-salt problem for most domestic purposes. The factor generally contributing to this shaker-salt problem is the tendency of the salt to become damp when exposed to humid conditions, causing a reduction in its fiowability and a caking of the salt. When salt is exposed to such humid conditions, moisture is deposited on the surfaces of the salt crystals. This moisture dissolves some of the salt and forms a brine coating over the surface of each crystal. Adjoining crystals of salt become linked together by films of the brine extending from one crystal to another and when such crystals become so linked, the salt lumps and has a reduced flowability. Further, when such crystals have become so linked, a subsequent reduction in the relative humidity of the air causes the brine film to evaporate and the crystals then become bonded together in the form of a cake. Consequently most domestic salt as used for culinary purposes today contains a conditioner or filler for the purpose of increasing the flowability by inhibiting dampening and/or caking tendencies to some degree. In this respect magnesium carbonate, tricalcium phosphate, calcium carbonate and starch have found general use. It has also been proposed to use such materials in combination with an edible water-insoluble soap in order to further improve the characteristics of the salt. Such soaps include the stearates, oleates, palmitates, laurates and like higher fatty acid salts of magnesium, calcium, aluminum, and the like. It has likewise been proposed to use such materials as oatmeal to absorb moisture preferentially. Also, rice is sometimes added to break up any caked salt which may form.

When the common conditioners, such as magnesium carbonate, tricalcium phosphate or calcium carbonate, are used to increase the flowability of the salt by increasing the resistance of the salt to caking and dampening, it has been found inadvisable to use more than 2% of such conditioner due to the fact that when larger amounts are used the salt tends to become dusty and a solution thereof is milky. When waterinsoluble soaps are used as conditioners it has been found inadvisable to use more than .05% of the same in order to avoid the formation of a scum on the surface of the water to which the salt composition is added. Combinations of the above conditioners as fillers in the salt seem to also include the same disadvantageous charac teristics as would be present with their individual use and such conditioners have therefore generally been added in the amounts of from 1 to 2% of the magnesium carbonate, tricalcium phosphate and/or calcium carbonate and about .05% of the water-insoluble soap though the addition of larger amounts of such conditioners would result in a salt having a more satisfactory flowability and resistance to caking. Thus, none of these conditioners either separately or in com-' bination as used today will as a practical matter maintain the salt in a satisfactory condition for a suflicient length of time in humid weather to eliminate the above-described shaker-salt problem.

The object of this invention is to provide an improved salt composition.

Another object is to provide a salt composition which has a high resistance to the effects of dampening.

Another obiect is to provide an improved salt composition which will remain free-flowing and resistant to lumping and caking when exposed to humid conditions for extended periods of time.

A still further object is to provide a salt composition which is substantially free from dust and which, when added to water, Jill give a clear scum-free brine.

Other objects of the invention will be apparent from the following description.

It has now been found that salt compositions to be used for culinary and table use which contain a precipitated magnesium or calcium silicate pow der such as are marketed under the trade names Magnesol and Silene respectively, possess increased resistance to the effects of dampening such as reduced Iiowability and caking when such compositions are subjected to humid and damp conditions. It has further been found that when an edible water-insoluble soap is added in combination with a precipitated magnesium or calcium silicate, a much greater amount of such insoluble soap can be tolerated such combinations without causing undesi .ble scumming in water sol tions of s ch compositions,

In the present invention it has been found that only a certain type of magnesium or calcium regular table salt provides This ty e is silicate when added to the desired salt compositions.

which is prepared by means of a volves the step of precipitation. the case of precipitated calcium silicate, a water solution of a hydrated silicate such as sodium silicate and a water solution of a soluble calcium salt, such as calcium chloride, are prepared. One solution is poured into the other 1.116. a precipitate is formed. The precipitate is :alcium silicate which may contain a small mount of sodium chloride occluded therewith. l-Iowever, most of the sodium chloride formed in ;he reaction remains in the solution and is separated from the calcium silicate by filtration. The .ecovered filtrate of calcium silicate is then dried to the desired moisture content. In the case of magnesium silicate, the precipitated magnesium silicate can be obtained in a similar manner by preparing a water solution of sodium silicate and a water solution of magnesium chloride. One solution is then poured into the other and the precipitate of magnesium silicate which may alsc contain a small amount of sodium chloride occluded therewith is separated by filtration from the sodium chloride solution. The precipitate of magnesium silicate is then dried to the desired. moisture content. As distinguished from naturally occurring magnesium and calcium silicates, such as, serpentine, seoiclite, enstatite, forsterite, spadaite, wollastonite, and the like, the silicates which are used in the present invention are precipitated magnesium and calcium silicates. These precipitated magnesium and calcium silicates are white, impalpable powders may be readily admixed with salt.

It has been found that at least about 0.5% of the precipitated magnesium or calcium silicate by weight of the salt should be used to obtain t. .5: improved results to a worthwhile degree. On the other hand, it is generally preferred to use no more than about by weight of the salt. When amounts in excess of 5% are used, they may provide some significantly greater beneficial results but they are undesirable because they create a dust problem in the salt, and when such salt compositions are added to water a milky sclution is formed.

Wh le the addition of precipitated ma nesium or calcium silicate alone increases the ability of the salt to resist the effects of dampening, it is generally preferred to add in combination with the precipitated magnesium or calcium silicate some quantity of an edible water-insoluble soap, such as, for example, magnesium stearate. The use of such a soap provides two benefits, namely, to reduce the tendency of the salt composition to cake, or secondly if any caking does occur, to provide for the easy disintegration of the lumps resulting from such caking. One unexpected advantage which has been discovered is that the insoluble soap when used in combination with the precipitated magnesium or calcium silicate can be used in a much greater proportion than has been possible heretofore without causing undesirable scumming when a water solution of such salt composition is prepared. The latter property is particularly advantageous in the case where the salt composition is used with water, clear solutions or clear soups because it is possible to achieve the desired salty taste without obtaining an undesirable scum on the surface of the water or soup. In the case of a precipitated magnesium ilicate, it is generally preferred to use about 0.05% of the insoluble soap by weight of the salt in order to obtain the additional bene fits and it is also generally preferred to use not more than 0.5% in order to avoid the problem of excessive scum formation. In'the case of precipitated calcium silicate, it is generally preferred to use about .02% of the insoluble soap by weight of the salt in order to obtain additional benefits and it is also generally preferred to use not more than about .2% in order to avoid the problem of excessive scum formation.

To compare the effect of precipitated magnesium or calcium silicate when combined with table salt with that of the other generally used. inhibitors such as calcium carbonate, magnesium carbonate or tricalcium phosphate, a test was devised to determine the resistance to the effects of dampening imparted to the salt by the various inhibitors or conditioners. Based on the observa tion of the practices of a large number of people in salting food, it was determined that an oscil lation motion of about 180 per minute with a 3" stroke having a line of motion-at about 20 to the horizontal represents the general action which occurs during food salting. On the basis of this, a machine was built to provide this motion. The number of strokes of the machine necessary to completely empty a shaker filled with a given quantity of substantially pure, dry table salt having a particle size of less than 20 standard mesh was noted and this value was used as a standard in the subsequent test. It then determined that when the amount of the salt removed from the shakers dropped to about for the standard number of motions by the machine, the salt had reached a minimum of acceptable fiowability. At this point the amount of moisture absorbed by the salt will also excessive caking. Two percent of each of calcium carbonate, tricalcium phosphate, magnesium carbonate, precipitated magnesium silicate precipitated calcium silicate were added to substantially pure, dry table salt and a number of shakers were filled with the aforementioned standard quantity and the open shakers were allowed to stand in an atmosphere having a as relative humidity. At one day intervals or less a shaker with each of the salt compositions was removed, weighed to determine moisture pick-up, capped with a standard perforated cap, and tested for fiowability. In this manner the num" ber of days the salt was capable of being exposed to 90% relative humidity before its flowability was reduced to the aforementioned 70% and t e amount of moisture absorbed in the process were determined. The following Tab-e I shows the results obtained in saidtest:

Table I Percen Days NaCl+2% calcium carbonate 0. i 5 1. 5 NaOH-2% tricalciumphosphate... O. 2. Z Na01+2% magnesium carbonate 0.83 2. 4 NaCll-2% magnesol (precipitated magne urn silicate) 2. 00 5. 7 NaCl+2% silenc E. F. (precipitated calcium silicate) 2. 00 5. 7

From Table I it will be noted that the pre cipitated magnesium and calcium silicate salt compositions had a resistance to the effects of dampening, as measured by days of exposure, approximately 2 /2 times greater than that of the magnesium carbonate or the tricalcium phosphate and about 4 times greater than that of calcium carbonate. The importance of such greatly increased resistance to dampening for the precipitated magnesium and calcium silicate salt compositions can be fully appreciated when one considers the fact that humid atmospheric conditions generally do not prevail for any consider able, sustained period of time. For example, should the relative humidity remain at about 90% for as long as five days, the flowability of tated calcium silicate salt composition with both the precipitated magnesium silicate salt scum formation than can be tolerated in s composition and the precipitated calcium silicate compositions containing the other fillers.

salt composition would continue to remain above It is apparent from the above tables that t the acceptable standard of 70% while the flow 5 table salt composition containing precipitat ability of the other inhibited salt compositions magnesium or calcium silicate is greatly superi would long before have been reduced to below to the salt compositions known heretofore. Tl

of time exceeding about five days, it will be seen in cats salt composition to the effects of dampenir that the fiowability of the precipitated magnewas found to be at least about 2 /2 times bett1 sium and calcium silicate salt compositions will, than the best of these inhibited salt compositior under most climatic and weather conditions, with the advantage that the present salt con. always remain substantially above the accepted positions can be exposed to high relative humidi fiowability of 70%. ties for longer periods of time than has bee. When an edible water-insoluble soap is added possible heretofore. As previously described, to ble salt the esistance of such salt composifurther important result as shown by these test greatly improved. For this reason, table salts of a metal stearate than can be tolerated with thi containing magnesium carbonate, calcium carother known inhibited salt compositions withou1 bonate or tricalcium phosphate may also advanproducing a scum formation on the surface of the tageously contain an insoluble soap, such as magsolution. This results in a more improved resistnesium stearate. Generally speaking, the reater ance of the salt composition to caking than can the amount of the metal stearate present the be obtained with pure salt or a salt composition greater the resistance to caking and the greater containing only the precipitated magnesium silithe ease of disintegration when such caking cate, the precipitated calcium silicate, or the occurs. However, as aforementioned, as the perother known conditioners.

centage of the metal stearate increases, there is While the invention has been described in dea concomitant disadvantage in that the salt comtail with specific examples, such examples are position when added to water produces an obillustrative only and the invention is understood jectionable scum. For this reason it has heretoas limited only as indicated in the appended fore generally been considered undesirable to add claims.

large amounts of such soaps to table salt com- What is claimed is:

positions. 1. A table salt composition of improved flow- On the other hand, when the insoluble salt is ability and non-caking qualities comprising a employed with a precipitated magnesium silicate mixture of shaker salt, a precipitated silicate it has been found that as much as about 10 times powder selected from the group consisting of premore of such soap may be added to the table salt cipitated magnesium silicate and precipitated than may be used with the common inhibitors. 4 calcium silicate, and an edible water-insoluble In the case of precipitated calcium silicate, it has soap powder. been found that as much as about 2 times more A table Salt mP PP lmprolfefi of such soap may be added to the table salt than ablllby and non-caklng qualltles CQ p S Salli may be used with t common inhibitors In of less than 20 standard mesh particle size, from order to compare the scum formation of insoluble about to precipitated magnesium sihcate soaps when added to a table salt containing P w a d r m ab ut J35 to 15% Of an ed ble fillers, such as the tricalcium phosphate and magwater-insoluble metal stearate powder.

nesium carbonate, a test was conducted to deter- A table S Composition of p v d fi W- mine how much magnesium stearate could be ability and non-coking quali i comprising l added to table salt containing 2% of the filler. f l ss t an 20 s d mesh particle Size, from The scum was evaluated visually when teaabout 0.5 to 5% precipitated magnesium silicate spoon of the salt composition was placed in 150 powder and from about .05 to 0.5% magnes um cc. of water at 140-150" F. The test was also run flp wd on a 2% precipitated magnesium silicate salt 4. A table salt composition of improved flowcomposition and 2% precipitated calcium silicate ability and non-caking qualities comprising salt salt composition and the following Table II preof less than 20 standard mesh particle size, from sents a compariso of t r ts Obta ned Whereabout 0.5 to 5% precipitated calcium silicate in Tolerance indicates the amount of magpowder and from about .02 to 0.2% of an edible nesium stearate which was added to the salt water-insoluble metal stearate powder. composition before visual scum formation was 5. A table salt composition of improved flownoticed: ability and non-caking qualities comprising salt Table II of less than 20 standard mesh particle size, from about .5 to 5% precipitated calcium silicate powder and fr m about .02 to 2 ma e Salt composition ent steal'ate powder.

stearate FRANK G. MILLER.

i l iii f, tttitlitl pit's tttttit:::::::::::::::::::: 813%.? References Cited in the file of this patent titliit:tint! Z1;tliittiitttttttttttlit: 8:25 UNITED STATES PATENTS Number Name Date From Table II it is clearly seen that a much 1,978,040 Daitz Oct. 23, 1934 greater percentage of the water-insoluble soap 2,234,484 Weinig Mar. 11, 1941 can be tolerated in both the precipitated mag- 2,333,873 4 Martin Nov. 9, 1943 nesium silicate salt composition and the precipi- 7 2,407,151 Glogau Sept. 3, 1946 

1. A TABLE SALT COMPOSITION OF IMPROVED FLOWABILITY AND NON-CAKING QUALITIES COMPRISING A MIXTURE OF SHAKER SALT, A PRECIPITATED SILICATE POWDER SELECTED FROM THE GROUP CONSISTING OF PRECIPITATED MAGNESIUM SILICATE AND PRECIPITATED CALCIUM SILICATE, AND AN EDIBLE WATER-INSOLUBLE SOAP POWDER. 